Campanula americana, the American bellflower, or tall bellflower, is an herbaceous wildflower and a member of the Campanulaceae family. Common binomial synonyms are Campanulastrum americana and Campanulastrum americanum. American bellflowers can be annual or biennial plants, depending on the season of germination.
center|thumb|399x399px|American bellflower flowers growing off of the central stalk
American bellflower flowers range in color from light blue to violet with a pale white ring at the throat of the flower. The flowers primarily bloom in the summer months of June, July and August. It is an unusual bellflower in that its flowers are flat, rather than its namesake bell shape.thumb|299x299px|American bellflower
Reproduction and Life History
The American bellflower is self-compatible and exhibits sequential hermaphroditism as a protandrous plant. Mating strategies are plastic, meaning they can adapt with changes in the environment, and dependent on pollinator abundance. When there are pollinators present in substantial numbers, the American bellflower reproduces via out-crossing, a reproduction strategy of breeding between different individuals. When there are low numbers of pollinators visiting, the plants are able to self-pollinate.
Pollen ranges in color from dark purple to light tan.
The fruiting bodies are capsules, displayed from August to March, and contain many seeds.
The amount of light and nutrients the maternal plant receives influences their offspring's germination timing. This germination timing from the maternal tissue in turn informs the life history strategy of the American bellflower, as it controls if the offspring will be an annual or biennial plant. Seeds that germinate in the fall produce annual plants and spring-germinating seeds produce biennial plants. Binneal plants produce a basal rosette in the first year, and bloom in the second year from a tall stalk that grows from the basal rosette.
Campanula is derived from the Latin word , which translates to "little bell" in reference to the typical bell-shaped flower of the genus. However, the American bellflower is an exception in its genus with its flat rather than bell shaped flower. With this morphological difference, a new genus titled Campanulastrum has been proposed for the American bellflower. The name Campanulastrum americana is used as another synonym for the American bellflower.
The species name of americana refers to the habitat range of America. American bellflowers grow from the Great Lakes region in southern Ontario south to Florida and from the Dakotas east to New York. The species is found in the US states of Alabama, Arkansas, Florida, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Louisiana, Maryland, Minnesota, Maine, Missouri, Mississippi, North Carolina, Nebraska, New Jersey, New York, Ohio, Oklahoma, Pennsylvania, South Carolina, South Dakota, Tennessee, Virginia, Wisconsin and West Virginia.
Campanula rapunculoides, or the creeping bellflower, is an invasive species from Europe and outcompetes the native American bellflower by choking its root systems.
American bellflowers attract a large number of native bees and are of conservational interest for these pollinators.